Line a baking sheet with nonstick foil.Assemble the sandwiches with a slice of ham and a half slice of cheese on each roll.Place the assembled sandwiches close together on the baking sheet.

In a small bowl combine the butter, sugar, mustard, and Worcestershire sauce.Microwave until the butter is just melted, about 30-60 seconds.Add the poppy seeds and stir until combined.

Drizzle the butter mixture evenly over the sandwiches. Keep in the fridge over night. Bake in the oven until the cheese has melted and the butter mixture starts to caramelize, about 10 minutes.Serve warm.